The iambic trimeter derives its name from its essential shape, which is three metrical units (hence trimeter) which are each basically iambic in form. The iambic metron has the following shape (where the x is an anceps, the - is a longum, and the u is a brevis):
Hence, reversing the current running though a wire will have the affect of reversing the direction of the magnetic force at a point some distance away from the wire. The affect that this has on the overall magnetic field depends on the shape of the wire.
The electric field is always perpendicular to the magnetic field, and both fields are directed at right-angles to the direction of propagation of the wave. In fact, the wave propagates in the direction . Electromagnetic waves are clearly a type of transverse wave. For a -directed wave, the electric field is free to oscillate in any direction which lies in the - plane. The direction in which the electric field oscillates is conventionally termed the direction of polarization of the wave. Thus, Eqs.